Dear George,
Lupus anticoagulant (LAC) assay has also been performed in dozens of our COVID-19 patients, however, very few of them got positive results, I don’t think that antiphospholipid antibody exists universally in COVID-19 patients. False positive results due to interference of anticoagulants may be an important reason for the high positive rate of LAC mentioned in these papers, the timing of collecting samples should be given attention.
I have responded to the letter from Harzallah I, et al. on JTH.